Fig. 4: O2•− fluorescence imaging of LX-2 cells with different degrees of activation.

a–e The LX-2 cells were incubated with different TGF-β1 concentrations or times. f Fluorescence intensities of a–e. Scale bar = 10 μm.The data were expressed as mean ± SD, n = 3. **p < 0.05 compared to the control group.